#include<bits/stdc++.h>
using namespace std;
#define int long long

int f[100][100];

signed main() {
	int n, k;
	cin >> n >> k;

	f[1][1] = 1;
	for (int i = 1; i <= n; i++)
		for (int j = 1; j <= k; j++)
			f[i][j] = (i > j) * f[i - 1][j] + f[j][j];
	cout << f[n][k];
	return 0;
}
